Graham Richardson has been a last-minute no-show on his Sky News program ‘Richo’, despite promising to use his show to respond to claims that he is ‘a person on interest’ in an Independent Commission Against Corruption (ICAC) investigation.

Throughout the day, the controversial political lobbyist and former Labor politician had been sending tweets to promote his appearance on the program.

Just two hours before the program’s scheduled start time he sent a message, declaring that he would give his ‘response to Fairfax’s report linking (him) to ICAC).

Yet at 8pm, his program Richo began with Peter Van Onselen at the helm, stepping into the hosting role without explanation.

'It looks like I'll be doing the rest of the show,' said Onselen, who had just finished hosting the lead-in program, 'PVO News Hour'.

Five days ago, Fairfax media published a report accusing Richardson of being ‘embroiled in a potentially explosive investigation’ by the Independent Commission Against Corruption.

Graham Richardson has been a last-minute no-show on his Sky News program ‘Richo’, despite promising to use his show to respond to claims that he is ‘a person on interest’ in an Independent Commission Against Corruption (ICAC) investigation

Just two hours before the program began, Graham Richardson had promised that he would respond to allegations that he is being investigated by ICAC

It’s alleged that Richardson was a lobbyist in a questionable property deal, after the anti-corruption body were made aware of a string of emails, sent between 2004 and 2010, reportedly exposed by the NSW ALP.

The contents of the emails or specific details of the alleged investigation are yet to be revealed.

'Graham was taken ill. These things happened. He didn't come into the studio,' said a Sky News spokesperson.

His no-show comes three months after the Australian political personality made a sudden exit while hosting the live broadcast of his Sky News show.

When the Richo program returned from an ad break, the 64-year-old, who is currently undergoing chemotherapy treatment, had been replaced by Sky News host Vanessa Grimm.

The host explained Richardson was not feeling well and a spokesperson for the network confirmed to Daily Mail Australia his sudden disappearance was due to illness.

'As most people are aware Richo is undergoing treatment. This evening during the show he had a turn. He is okay and will be back next week,' the statement said.

The former Labor powerbroker has suffered from chondrosarcoma - a condition that sees the victim plagued with cancerous cysts - for more than 15 years, and began a new experimental form of chemotherapy earlier this year.

The 64-year-old is currently undergoing experimental chemotherapy treatment for a rare condition called chondrosarcoma, which sees his pelvic region plagued with cancerous cysts

'These things won’t kill me but the condition is rare so it’s time to look at new treatment,' he told the Daily Telegraph in February.

'The drugs are experimental. I’ll be the 13th person in the country to have tried them.'

The former New South Wales senator said he wasn't concerned about the treatment interfering with his job hosting the Sky program.

'I may not look the best, but I should still be able to do my shows.'

Richardson has had several operations on the cysts, which are located in his pelvic region.

A spokesperson for Sky News said Richardson has taken 'a turn' during the program but 'he is okay'